In a UMTS (Universal Mobile Telecommunications System) network, long-term evolution (LTE) is under study for the purpose of achieving even higher data rates, lower delays and so on (non-patent literature 1). In LTE, as multiple access schemes, a scheme that is based on OFDMA (Orthogonal Frequency Division Multiple Access) is used in downlink channels (the downlink), and a scheme that is based on SC-FDMA (Single Carrier Frequency Division Multiple Access) is used in uplink channels (the uplink).
Also, successor systems of LTE (referred to as, for example, “LTE-advanced” or “LTE enhancement” (hereinafter referred to as “LTE-A”)) are under study for the purpose of achieving further broadbandization and increased speed beyond LTE. In LTE (Release 8) and LTE-A (Release 9 and later versions), MIMO (Multi-Input Multi-Output) techniques are under study as radio communication techniques to transmit and receive data using a plurality of antennas and improve spectral efficiency. According to MIMO techniques, a plurality of transmitting/receiving antennas are provided in a transmitter/receiver, so that different transmission information sequences are transmitted from different transmitting antennas at the same time.